198 research outputs found

    Formaldehyde in screen printing indoor

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    The presence of formaldehyde in air samples has been detected in five screen printing facilities in Novi Sad, Serbia. Air samples were sampled continuously during 4 hours, and concentration levels of formaldehyde was determined by UV-VIS spectrometry at 580 nm. The range of formaldehyde concentrations was from 0.413 to 0.836 ppm. Comparison of the detected concentration levels with the permissible exposure limit of 0.75 ppm (the OSHA standard) indicated that the formaldehyde concentration in facility 5 was 1.11 times higher than prescribed value

    Representations of Double Affine Lie algebras

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    We study representations of the double affine Lie algebra associated to a simple Lie algebra. We construct a family of indecomposable integrable representations and identify their irreducible quotients. We also give a condition for the indecomposable modules to be irreducible, this is analogous to a result in the representation theory of quantum affine algebras. Finally, in the last section of the paper, we show, by using the notion of fusion product, that our modules are generically reducible

    Density functional theory based effective fragment potential method

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    The effective fragment potential (EFP) method, is a discrete method for the treatment of solvent effects, originally formulated using Hartree–Fock (HF) theory. Here, a density functional theory(DFT) based implementation of the EFP method is presented for water as a solvent. In developing the DFT based EFP method for water, all molecular properties (multipole moments, polarizabilitytensors, screening parameters, and fitting parameters for the exchange repulsion potential) are recalculated and optimized, using the B3LYP functional. Initial tests for water dimer, small water clusters, and the glycine–water system show good agreement with ab initioand DFT calculations. Several computed properties exhibit marked improvement relative to the Hartree–Fock based method, presumably because the DFT based method includes some dynamic electron correlation through the corresponding functional.The following article appeared in Journal of Chemical Physics 118 (2003): 6725, and may be found at doi:10.1063/1.1559912.</p

    Modeling Styrene−Styrene Interactions †

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    The Effective Fragment Potential: Small Clusters and Radial Distribution Functions

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    The effective fragment potential (EFP) method for treating solventeffects provides relative energies and structures that are in excellent agreement with the analogous fully quantum [i.e., Hartree-Fock (HF), density functional theory(DFT), and second order perturbation theory (MP2)] results for small water clusters. The ability of the method to predict bulk water properties with a comparable accuracy is assessed by performing EFP molecular dynamics simulations. The resulting radial distribution functions (RDF) suggest that as the underlying quantum method is improved from HF to DFT to MP2, the agreement with the experimental RDF also improves. The MP2-based EFP method yields a RDF that is in excellent agreement with experiment

    Milieu effects on the Dark Triad traits and their sex differences in 49 countries

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    Most research on the development of personality traits like the Dark Triad (i.e., narcissism, Machiavellianism, and psychopathy) focuses on local effects like parenting style or attachment, but people live in a larger society that may set the stage for any local effects. Here we paired nation-level data on the traits from 49 nations with several milieu indicators (e.g., life expectancy, homicide rates) from three timepoints (and change among them) where the average participant (≈ 22yo) would have been a child (≈ 6yo), a pre-teen (≈ 11yo), and a teenager (≈ 16yo). Congruent with previous research, variance in narcissism was far more sensitive to variance in milieu conditions in general and across all three time points than variance in Machiavellianism or psychopathy. The milieu conditions differentiated the traits somewhat with income and education revealing negative correlations with narcissism, positive correlations with Machiavellianism, and null correlations with psychopathy. Sex differences in Machiavellianism and narcissism were correlated with homicide rates across the three timepoints. The evidence that changes in milieu conditions in ones' past predicts the traits was erratic, but larger sex differences in the traits were associated with decreased life expectancies and homicide rates between childhood and pre-teens.info:eu-repo/semantics/acceptedVersio

    Potential Energy Surfaces of Si m

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    Design and Implementation of Scientific Software Components to Enable Multiscale Modeling: The Effective Fragment Potential (QM/EFP) Method

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    The design and development of scientific software components to provide an interface to the effective fragment potential (EFP) methods are reported. Multiscale modeling of physical and chemical phenomena demands the merging of software packages developed by research groups in significantly different fields. Componentization offers an efficient way to realize new high performance scientific methods by combining the best models available in different software packages without a need for package readaptation after the initial componentization is complete. The EFP method is an efficient electronic structure theory based model potential that is suitable for predictive modeling of intermolecular interactions in large molecular systems, such as liquids, proteins, atmospheric aerosols, and nanoparticles, with an accuracy that is comparable to that of correlated ab initio methods. The developed components make the EFP functionality accessible for any scientific component-aware software package. The performance of the component is demonstrated on a protein interaction model, and its accuracy is compared with results obtained with coupled cluster methods

    On the complete classification of the unitary N=2 minimal superconformal field theories

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    Aiming at a complete classification of unitary N=2 minimal models (where the assumption of space-time supersymmetry has been dropped), it is shown that each modular invariant candidate of a partition function for such a theory is indeed the partition function of a minimal model. A family of models constructed via orbifoldings of either the diagonal model or of the space-time supersymmetric exceptional models demonstrates that there exists a unitary N=2 minimal model for every one of the allowed partition functions in the list obtained from Gannon's work. Kreuzer and Schellekens' conjecture that all simple current invariants can be obtained as orbifolds of the diagonal model, even when the extra assumption of higher-genus modular invariance is dropped, is confirmed in the case of the unitary N=2 minimal models by simple counting arguments.Comment: 53 pages; Latex; minor changes in v2: intro expanded, references added, typos corrected, footnote added on p31; renumbering of sections; main theorem reformulated for clarity, but contents unchanged. Minor revisions in v3: typos corrected, footnotes 5, 6 added, lemma 1 and section 3.3.2 rewritten for greater generality, section 3.3 review removed. To appear in Comm. Math. Phy
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